So, do the brakes start dragging after they are applied a few times, or even if they are not applied?
Do the front brake drums pull off easily when hot and dragging, or do you have to wait until they cool?
What does the wear pattern look like on the shoes, or are there too few miles to see it yet?
Did you set the shoe pairs in the drums before assembly to ensure the arcs were the same? Although what typically happens is freshly turned drums contact only the center 50-75% of the new shoes. And I can't see how that would cause your problem.
What shape are the bearings in? Some of the very low priced shoes, drums, bearings, and wheel cylinders are poor quality. For example. I currently have a problem with some fairly new Pep Boys shoes that were causing lock-up on one rear wheel under moderate to heavy braking. When I pulled the drum, both shoe linings had a couple very rough spots, kind like small peaks and pits. I sanded them down with 80 grit, which fixed the problem, but I plan to replace the shoes with Wagners. Drums looked good.